The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 31, 1982
Filed:
Dec. 01, 1980
Sadao Suzuki, Tokyo, JP;
Yoshino Kogyosho Co., Ltd., , JP;
Abstract
A method for injection molding a particularly elongated tubular parison having a closed bottom and assuring consistently uniform wall thickness in the tube wall, is disclosed. The method involves injection molding an open bottom tubular member, and thereafter forming a bottom wall integrally with the tubular member in a separate injection molding step in which a molten polymer is injected into a mold cavity defined, in part, by the bottom end of the tubular member. During the first injection molding step, the core mold is held at both ends by the other components of the mold assembly so that there is no possibility of eccentric misplacement of the elongated core in the mold cavity due to flexing of the core, which would cause non-uniformity in wall thickness of the molded tube. The open bottom of the tube is closed by injecting additional polymer during the second injection molding step, wherein a portion of the mold cavity is defined by the bottom end of the previously formed tubular member, so that the injection molded bottom wall is integrated to the tube parison in accurate relative position to the tubular wall.